diff --git a/assets/misuzu.js/messages/messages.js b/assets/misuzu.js/messages/messages.js
index 5edb46b..5799d56 100644
--- a/assets/misuzu.js/messages/messages.js
+++ b/assets/misuzu.js/messages/messages.js
@@ -160,6 +160,7 @@ const MszMessages = () => {
         if(msgsRecipient !== undefined)
             msgsRecipient.onUpdate(async info => {
                 msgsReply.setRecipient(typeof info.id === 'string' ? info.id : '');
+                msgsReply.setWarning(info.ban ? `${(typeof info.name === 'string' ? info.name : 'This user')} has been banned and will be unable to respond to your messages.` : undefined);
             });
 
         msgsReply.onSubmit(async form => {
diff --git a/assets/misuzu.js/messages/reply.jsx b/assets/misuzu.js/messages/reply.jsx
index 3786899..3b0c041 100644
--- a/assets/misuzu.js/messages/reply.jsx
+++ b/assets/misuzu.js/messages/reply.jsx
@@ -11,6 +11,8 @@ const MszMessagesReply = function(element) {
     const parserSelect = form.querySelector('.js-messages-reply-parser');
     const saveBtn = form.querySelector('.js-messages-reply-save');
     const sendBtn = form.querySelector('.js-messages-reply-send');
+    const warnElem = form.querySelector('.js-reply-form-warning');
+    const warnText = warnElem instanceof Element ? warnElem.querySelector('.js-reply-form-warning-text') : undefined;
 
     let submitHandler;
     form.addEventListener('submit', ev => {
@@ -133,6 +135,18 @@ const MszMessagesReply = function(element) {
 
     return {
         getElement: () => element,
+        setWarning: text => {
+            if(warnElem === undefined || warnText === undefined)
+                return;
+
+            if(text === undefined) {
+                warnElem.hidden = true;
+                warnText.textContent = '';
+            } else {
+                warnElem.hidden = false;
+                warnText.textContent = text;
+            }
+        },
         setRecipient: userId => {
             for(const field of form.elements)
                 if(field.name === 'recipient') {
diff --git a/src/Messages/MessagesRoutes.php b/src/Messages/MessagesRoutes.php
index 6938bc7..3398116 100644
--- a/src/Messages/MessagesRoutes.php
+++ b/src/Messages/MessagesRoutes.php
@@ -174,6 +174,7 @@ class MessagesRoutes extends RouteHandler {
         return [
             'id' => $userInfo->getId(),
             'name' => $userInfo->getName(),
+            'ban' => $this->usersCtx->hasActiveBan($userInfo),
             'avatar' => $this->urls->format('user-avatar', [
                 'user' => $userInfo->getId(),
                 'res' => 200,
diff --git a/templates/messages/compose.twig b/templates/messages/compose.twig
index 7b4fda6..e32b206 100644
--- a/templates/messages/compose.twig
+++ b/templates/messages/compose.twig
@@ -40,6 +40,11 @@
 
                 <form class="messages-reply-form js-messages-reply-form">
                     {{ input_hidden('recipient', '') }}
+                    <div class="warning js-reply-form-warning" hidden>
+                        <div class="warning__content">
+                            <p class="js-reply-form-warning-text"></p>
+                        </div>
+                    </div>
                     <div class="messages-reply-subject">
                         {{ input_text('title', 'messages-reply-subject-input', '', 'text', 'Subject', true) }}
                     </div>